Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02440808 2003-09-12
FORK LIFT ATTACHMENT FOR MULTI-PURPOSE BUCKET
BACKGROUND OF THE INVENTION
1. Field of the Invention. This invention relates generally to the
field of fork lift attachments to convert a multi-purpose bucket of a
loader into a fork lift and more particularly to the field of doing so in a
removable manner that is easy to install and does not damage the
bucket.
2. Discussion of the Background. In the construction and
agriculture industries loaders are often used as multi-functional pieces
of equipment. Some of these loaders make use of a multi-purpose
bucket in order to be more versatile and have one piece of equipment
able to perform many tasks. These multi-purpose buckets are also
referred to as 4-in-I buckets or clam shell buckets. The bucket has
two jaws that are pivotally mounted to each other with their positions
relative to each other being controlled by hydraulic cylinders. The
bucket is then otherwise operated and moved as any regular bucket
would be on a loader.
There have been fork lift attachments for regular buckets, such
as U.S. Patent No. 6,022,184 to Friediand, wherein the attachments
allow for the temporary conversion of a regular bucket to perform fork
lift jobs. This conversion ability is very advantageous in that it allows
a single piece of equipment to be used for different functions without a
major investment in separate specialized equipment.
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For multi-purpose buckets, prior fork lift attachments have
relied upon cumbersome and sometimes unsecured means of
attachment. Examples are illustrated by U.S. Patent No. 3,667,633 to
Cappella and U.S. Patent Nos. 6,287,070, 6,527,497 and 6,547,508
to Perry. These designs have serious drawbacks. In practice the tips
of the fork lift tine often are pushed upward, intentionally or
unintentionally, creating forces that may dislodge the fork lift
attachments. The result may be an insecure fork lift or dropped or
damaged cargo which may cause personal injury or property damage.
Inadvertent dropping of the fork lift attachment from the bucket can
also occur if the jaws of the multi-purpose bucket open, even if only
partially.
A second shortcoming of these prior designs is the
components that are used. Some, such as in the Perry design, have
large steel plates that must be placed in the bucket with attached T or
I beams. These can weigh a significant amount, thus reducing the
useable payload weight. In addition the large, heavy components
necessarily cannot be easily installed by an individual and can pose
difficulties in field installations. Further, the Perry design has an
expensively fabricated tine component which is necessary in order to
have the front of the tines be at ground level. The fabrication to
obtain such a configuration while maintaining strength is very
expensive and involved.
Another shortcoming of some designs is the use of semi-
permanent bolts or other fasteners to secure the fork lift attachments
to the bucket. Placement of holes or other similar permanent
alterations to the bucket are not advisable, as it diminishes the
integrity of the bucket and can initiate degradation or shortening of the
life of the bucket. If the machine is a rental or loaned piece of
equipment, such alterations are normally not permitted.
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SUMMARY OF THE INVENTION
The present invention involves the easy mounting of the within
fork lift attachment to convert the multi-purpose bucket of a loader into
a fork lift. The attachment is very secure and reduces the risk of
slippage or movement of the fork lift attachment while in operation,
even if the multi-purpose bucket opens partially or is reverse loaded.
The design is simple and the location of the tines on the underside of
the bucket allows for easy mounting and use. The fork tines can be
set on the ground and the bucket attached and secured by only a
single person. There is no need to manually lift the attachment or any
of its parts into or over the bucket for installation.
The attachment includes a security latch that is easily placed
and readily visible to check for secure installation. Further, the latch
acts to tighten the integration of the fork lift attachment to the bucket.
The latch also acts as a load bearing structure to transfer forces to the
most sturdy and rigid portions of the bucket, which are the leading
edge of the upper jaw and rear and leading edge of the lower jaw of
the bucket.
The installation does not damage the bucket as there are no
holes or mounting plates required. Further the fork lift attachment can
be easily moved and stored as its parts are compact. The fork lift
attachment components themselves are simple in design and
relatively inexpensive with no massive, heavy components, thus
allowing for easy installation and maintenance.
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BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a loader with a clamped multi-purpose bucket
attached as it would essentially appear when being used as a loader
bucket. FIG. 1 also illustrates the fork lift attachment of the present
invention secured to the bucket.
FIG. 2 illustrates a multi-purpose bucket opened showing the
two major portions or jaws of this type of bucket.
FIG. 3 illustrates one fork lift attachment with three alternative
latch components that would be selected to be used with different
types or brands of buckets.
FIG. 4 illustrates a side view of a fork lift attachment along with
the two jaws of the multi-purpose bucket as it is being positioned for
installation.
FIG. 5 as in FIG. 4 is a side view showing the installation
process as the upper jaw of the bucket is first brought into contact
with the latch of the fork lift attachment.
FIG. 6 like in FIG. 5 is a side view with the top jaw being closed
onto the latch thus securing the fork lift attachment.
FIG. 7 illustrates two fork lift attachments with links or chains as
visible safeties holding the latches in the position of installation as
they would be in FIG. 6.
FIG. 8 illustrates a perspective view of two fork lift attachments
installed on a multi-purpose bucket with the links in place as shown in
FIG. 7.
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DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a multi-purpose bucket 2 on a typical loaderl.
The bucket 2 as a whole is moveable on arms 4 as in such loaders 1.
The bucket 2, as better seen in FIG. 2, has two major portions or jaws
6 and 8 that are pivotally mounted to each other at 7 and moveable
relative to each other. In an opened position, the lower jaw 8 when
raised allows the upper jaw 6 to be useable as a grader blade. The
two jaws 6 and 8 in cooperation can also act as a claw for grasping
and lifting and moving items in the field. In another configuration, the
lower jaw 8 can act as a scraper for earth surface treatment. When
the two jaws are closed without the fork attachment, it operates as a
regular bucket. This versatility of such a typical multi-purpose bucket
2 is well known. However, the function that is not present without an
attachment is the fork lift function. In the clamped position of FIG. 1,
the rear edge 10 (see FIG. 2 again) of the lower jaw 8 meets the
bottom edge 12 of the upper jaw 6 to form the bucket with the fork
attachment 20 in FIG. 1 clamped between the two jaws of the bucket.
The methods and attachments herein accomplish this extra
functionality by the addition of a fork lift attachment 20 to the multi-
purpose bucket 2 in an easy and secure manner that does not
damage the bucket 2.
FIG. 3 illustrates the fork lift attachment 20 of the present
invention which can be installed on the multi-purpose bucket 2 and
are usually installed in pairs. Each fork lift attachment 20 is
comprised of a tine 22 that has a tip 24 and a heel 26. The fork lift
attachment 20 also has a vertical extension 50 whose function as a
cargo barrier will be more fully explained below. On the top side of
the tine 22 is a slot 30 formed in part by member 32 positioned
between the tip 24 and the heel 26. The slot 30 is also preferably
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formed in part by a base 28 which is on the top side of the tine 22 and
below a portion of the member 32. A rear bearing point 35 is also
provided on the top side of the tine 22 between the slot 30 and the
heel 26 with a hinge point 33 being located on the heel 26 of the tine
22. A latch 36 is rotatably attached to the hinge 33 on the tine 22 and
as shown in FIG. 3 may have different configurations including those
of 36a, 36b and 36c. 36a is useable for John Deere multi-purpose
buckets and Gannon Buckets. 36b is useable for Caterpillar and
Komatsu multi-purpose buckets and 36c is useable for Case buckets.
Most other multi-purpose buckets will use one of these three styles.
FIG. 4 represents a side view of the fork lift attachment 20
resting on a surface, such as the ground. As the tine 22 nests on the
bottom of the bucket when installed, there is no need to manually lift
the tine 22 onto or into the bucket.
FIG. 4 further illustrates that when initially joining the bucket 2
and fork lift attachment 20, the jaws 6 and 8 of the bucket 2 are
opened and the entire bucket 2 is rotated forward. This allows the
bottom jaw 8 to engage the fork lift attachment 20 (similar to slipping a
foot into a slipper). The operator places the leading edge 14 of the
bottom jaw 8 in the slot 30 between the top member 32 and the base
28. The bottom surface 13 of the bottom jaw 8 of the bucket 2 rests
on the rear bearing point 35. The rear edge 10 of the bottom jaw 8
when in place is approximately even with the hinge point 33 on the
heel 26 of the tine 22.
In the preferred embodiment, there are multiple hinge points
such as 33 and 33a as in FIG. 3 to allow different locations of the
latch 36a, 36b, or 36c and the adjustment of the fork lift attachment
20 to fit the length of the bottom surface 13 of the bottom jaw 8 from
the leading edge 14 to the rear edge 10. In FIGS. 4, 5 and 6, the
more rearward hinge point 33 is shown being used. In FIG. 4 a front
bearing point 34 on the slot forming member 32 is illustrated which
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interacts with the top of the leading edge 14 of the bottom jaw 8 to
transmit forces. Thus the downward forces transmitted to the bucket
2 during loading of the tines 22 are localized by the front bearing point
34 on the leading edge 14, where there is the greatest reinforcement
and weight bearing ability.
The latch 36 in each of the preferred embodiments (e.g., see
version 36c in FIG. 3) is composed of a steel flat 37 with a hinge collar
38 at one end. The flat 37 must be thick and strong enough to
withstand bending forces that will occur when the leading edge 12 in
FIG. 6 is forced against the rear contact point 42, which in turn will
force the front surface of the flat 37 of the latch 36 to contact the rear
edge 10 of the jaw 8. In the preferred embodiment, the rear contact
point 42 in FIG. 6 is located farther from the hinge point 33 than the
front contact point between the flat 37 and the edge 10. This creates
a fulcrum at the front contact point. By a lever action at the fulcrum
point when the rear contact point is forced forward, the hinge 33 will
be forced rearward. Also the latch 36 when forced upward will pull the
attachment 20 and force the rear bearing point 35 against the bottom
13 of the bucket 2. This action cinches the attachment 20 to the
bucket 2 and concentrates the forces at the bearing points 34 and 35.
On the front side of the latch 36 (see again as an example 36c
in FIG. 3) is a safety stop 40. In the preferred embodiment the safety
stop 40 is a rod or round stock welded on the front of the flat 37 of the
latch 36. The stop may also be an extension 41, such as in version
36a in FIG. 3 designed for a specific bucket. Similarly the rear contact
point 42 in the preferred embodiment is a rod or round stock welded
on the rear face of the flat 37 of the latch 36. The rear contact point
42 interfaces with the leading edge 12 (see FIG. 6) so as to create a
vector force generally forward on the flat 37.
A wedge piece 44 in the latch versions 36a, 36b and 36c of
FIG. 3 is a flat piece welded to rear contact point 42 and to and
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extending beyond the top 43 as shown. The top 43 in this regard is
the end of the flat 37 away from the hinge 38 of the latch 36. A hole
45 is broached into the end of the wedge 44 piece to accommodate
the hook 62 (as shown in FIG. 7) on the safety link 60 as will be
described in more detail below. This wedge 44 (see again FIG. 5)
operates to allow the leading edge 12 of the top jaw 6 to smoothly
engage the latch 36 and get into position against the rear contact
point 42. As an alternative, the purpose and safety feature of the
latch 36 may be accomplished by a single fabrication piece or a
different configuration understood to accomplish the same or some of
the functions described herein.
The installation of the fork lift attachment 20 onto a multi-
purpose bucket 2 is progressively illustrated in FIGS. 4, 5 and 6 with
FIG. 4 being a starting position.
FIG. 5 is a side view with the top jaw 6 of the bucket 2 closing
on the bottom jaw 8 and first engaging the latch 36. As illustrated,
leading edge 12 contacts the wedge 44 on the latch 36. This causes
the latch 36 to rotate, clockwise in this view, about the hinge point 33
and a front contact point of the flat 37 to move towards contact with
edge 10.
FIG. 6 illustrates the latch 36 rotated about the hinge point 33
as the front of the latch 36 at a front contact point on the flat 37 is
forced against the rear edge 10 in response to the top jaw 6 forcing
the rear contact point 42 forward. In FIG. 6 the latch 36 is held in this
configuration by hydraulic forces causing the leading edge 12 of the
top jaw 6 to contact the rear contact point 42 of the latch 36.
In FIG. 6 the latch 36 has a safety stop 40. The stop 40 acts
as a safety to prevent the latch 36 from slipping down and out from
the clamp of edge 12 and edge 10, due to any reverse loading on the
tip 24 of the tines 22.
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The rear contact point 42 by way of the hydraulic force through
edge 12 causes rotational forces in the latch 36 about the fulcrum
point of the front contact point of the flat 37 and edge 10. The force
of edge 12 pushes against the rear contact point 42 and forces latch
36 forward. Since the latch 36 is attached to the heel 26 of the tine 22
at the hinge point 33, the heel 26 of the tine 22 is pulled rearward with
the rear bearing point 35 pressing against the bucket bottom surface
13 of the bucket 2. This, in turn, puts pressure on the fork lift
attachment 20 to move the slot 30 backward against the leading edge
14 of the bucket 2. The force of the backward movement at the slot
30 is opposed by the edge 14 of the bottom jaw 8 of the bucket 2
against the top member 32 of the slot 30 and against the front bearing
point 34. This series of actions acts as a cinch of the fork attachment
around the bottom surface 13 of the bucket 2 thus stabilizing the
15 fork lift attachment 20.
The connection of the fork lift attachment 20 with the bucket 2
thus is accomplished with multiple securing techniques to stabilize the
fork lift attachment 20 and form a rigid union between the fork lift
attachment 20 and the multi-purpose bucket 2. The hydraulic controls
20 of the multi-purpose bucket 2 cinch the connection and insure a rigid
interaction between the components. The result is an efficient force
transfer between the components during loading. The tight
connection, forced by the hydraulics and the bearing points 34 and 35
and the rear contact point 42, insures that there is a rigid connection
without any easy freedom of movement of the fork lift attachment 20
relative to the bucket 2. All of the benefits result without heavy or
cumbersome plates or cross pieces, and without bolts or permanent
alterations to the bucket 2.
Further, the installation can readily be accomplished by the
operator as no parts of the fork lift attachment 20 need to be manually
lifted into or onto the bucket 2. The tines 22 merely rest on the
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ground or platform and the bucket 2 by hydraulics is placed on the top
side of the tines 22 to engage the slot 30 by the leading edge 14 of
the bucket 2. The closing of the latch 36 and the cinching of the
connection occurs by hydraulically controlling the closure of the multi-
purpose bucket 2. The attachment is thus easily accomplished
without any holes, bolts or heavy components.
A further improvement with added safety includes the
adjustable link or chain 60 (see FIG. 7) from the slot forming member
32 to the latch 36. The link 60 in this embodiment is attached to the
top of the slot forming member 32 and acts as another safety to
prevent the latch 36 from moving open on the hinge point 33 and
thus, loosen or disengage from the rear edge 10 of the bucket 2. This
could occur if the clamping action or hydraulic forces are lost or weak
or unintentionally released allowing edge 12 to move away from the
latch 36 or if the tines are reverse loaded. In the preferred
embodiment, the adjustment at 64 is a bolt 66 welded to the end of
the link 60 opposite the end with the hook 62 (in the illustration the
link 60 is a chain). The bolt extends through the slot forming member
32 and is attached thereto with a nut that is used to shorten the total
length of the link 60. The adjustment at 64 allows the link 60 to be
attached to the latch 36 and then adjusted by shortening to provide a
taut link. This minimizes any freedom in the attachment cinch. In the
preferred embodiment the adjustment is a bolt, though any suitable
adjuster could be used.
Another feature of the fork lift attachment 20 aids the fork lift
function. In this regard vertical extensions 50 of the fork lift
attachment 20 extend upward from the front of the slot 30. The
extensions 50 operate as a load or cargo barrier or backstop to
prevent loads, such as round stock or pipes and similar items from
sliding or rolling into the bucket 2 when picked up and the fork lift tines
22 are rotated upward as is illustrated in FIG. 1. It also, at a suitable
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height, serves to allow the operator of the loader to see the location of
the tine 22. This is necessary when the ends 24 of the tines 22 are
not visible over the bucket 2 and load or other parts of the machine.
The extensions 50 also have lifting aids 52 (see FIGS. 6 and 7) so
that the extension 50 may be clamped and moved by the bucket 2 or
moved by chains, ropes or by hand for positioning using handles 54.
While several embodiments of the present invention have been
shown and described in detail, it is to be understood that various
changes and modifications could be made without departing from the
scope of the invention.
